Study on the catalytic degradation of sodium lignosulfonate to aromatic aldehydes over nano-CuO:Process optimization and reaction kinetics

As one of the few renewable aromatic resources,the research of depolymerization of lignin into highvalue chemicals has attracted extensive attention in recent years.Catalytic wet aerobic oxidation(CWAO)is an effective technology to convert lignin like sodium lignosulfonate(SL),a lignin derivative,into aromatic aldehydes such as vanillin and syringaldehyde.However,how to improve the yield of aromatic aldehyde and conversion efficiency is still a challenge,and many operating conditions that significantly affect the yield of these aromatic compounds have rarely been investigated systematically.In this work,we adopted the stirred tank reactor(STR)for the CWAO process with nano-CuO as catalyst to achieve the conversion of SL into vanillin and syringaldehyde.The effect of operating conditions including reaction time,oxygen partial pressure,reaction temperature,SL concentration,rotational speed,catalyst amount,and NaOH concentration on the yield of single phenolic compound was systematically investigated.The results revealed that all these operating conditions exhibit a significant effect on the aromatic aldehyde yield.Therefore,they should be regulated in an optimal value to obtain high yield of these aldehydes.More importantly,the reaction kinetics of the lignin oxidation was explored.This work could provide basic data for the optimization and design of industrial operation of lignin oxidation.

A simple and efficient method for solvent-free iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid by grinding method

Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides several advantages such as environmentally friendly,short reaction times,high yields,non-hazardous and simple work-up procedure.

THE SOLID STATE ALDOL CONDENSATION REACTION OF ACETYLFERROCENE AND AROMATIC ALDEHYDES

The aldol condensation reactions of acetylferrocene with several aromatic aldehydes have been studied in the solid state.The results showed that they revealed different reactivities in the solid slate from that in solution and eight compounds have been prepared. Their structures have been characterized by UV,IR,1~HNMR,HS and elemental analysis.

THE REACTION OF AROMATIC ALDEHYDES WITH p-NITROBENZYLLIBUTYLTELLURONIUM BROMIDE BY PHASE TRANSFER CATALYSIS

Under the condition of solid-liquid phase transfer catalysis, olefins were obtained by the reaction of p-nitrobenzyldibutyltelluronium bromide with aromatic aldehyde.Under the condition of liquid-liquid phase transfer catalysis,however,different products were obtained due to the reactivity of different bases or aldehydes.

Cu-catalyzed deoxygenative gem-hydroborylation of aromatic aldehydes and ketones to access benzylboronic esters

Organoboron compounds are widely used in synthetic chemistry,pharmaceutical chemistry and material chemistry.Among various organoboron compounds,benzylboronic esters are unique and highly reactive,making them suitable benzylation reagents.At present,the synthetic methods for the syntheses of benzylboronic esters are still insufficient to meet their demands.It is necessary to develop novel and practical methods for their preparation.In this work,a novel copper‐catalyzed deoxygenative gem‐hydroborylation of aromatic aldehydes and ketones has been developed.This direct and operationally simple protocol provides an effective approach for the synthesis of a variety of primary and secondary benzylboronates,in which broad functional group tolerance was presented.Widely available B2pin2(pin=pinacol)was used as the boron source and alcoholic proton was applied as the hydride source.

Condensation of Aromatic Aldehydes with Isopropylidene Malonate or 5,5-Dimethyl-1,3-cyclohexanedion without Catalyst

The condensation of aromatic aldehydes with isopropylidene malonate or 5,5-dimethyl-1,3-cyclohexanedione is carried out by DMF as solvent without catalyst.

THE CONDENSATION REACTION OF BIS(PERFLUOROALKANESULFONYL)METHANES WITH AROMATIC ALDEHYDES

The ccndensation reactions occurred when heating bis(perfluoroalkane- sulfonyl)methanes with aromatic aldehydes in acetic acid anhydride and gave high yields of 1-aryl-2,2-di(perfluoroalkanesulfonyl)ethylenes The perfluoroalkanesulfonyl groups R_FSO_2 are known as the strongest electron-attracting substituents^(1-2).This property is often used in the activation of C-C multiple and 2,2'-C-H bonds.The synthesis and reactions of perfluoroalkanesulfonyl substituted alkenes and alkynes are of great interest in synthetic organic chemistry^(3-6). Recently,Hanack^7 reported the preparation of 2-aryl-l-(perfluoroalkane- sulfonyl)acrylonitrile R_FSO_2C(CN)=CHAr.However,he failed to obtain the 1,1-di(perfluoroalkanesulfonyl)alkenes by the Knoevenagel reaction of bis(perfluoroalkanesulfonyl)methane with aldehydes.

THE UNUSUAL REDUCTION OF SOME AROMATIC ALDEHYDES BY SODIUM BOROHYDRIDE

Two aromatic aldehydes are found to be reduced by an unusual way by sodium borohydride in the presence of water to yield the corresponding methyl substituted aryl compounds.

The Condensation of Aromatic Aldehydes with Acidic Methylene Compounds in Water

The condensation of aromatic aldehydes with acidic methylene compounds such as malononitrile, methyl cyanoacetate, cyanoacetamide, 5,5-dimethyl-1,3-cyclohexanedione, bartbituric acid and 2-thiobarbituric acid proceeded very efficiently in water in the presence of triethylbenzylammonium chloride (TEBA) and the products were isolated simply by filtration.

Condensation Reaction of α-Aroyl-α-acetyl Ketene Cyclic Dithioacetals with Aromatic Aldehydes

The title compounds 3 and 4 condensed with aromatic aldehydes to give a--aroylsicinnamoyl ketene cyclic dithioacetals 5 and 6 with sodium ethoxide as the base. The stereochemistryofs and 6 was assigned as E-configuration by 1H NMR.

An Efficient System TiCl_4-Al for the Homocoupling Reaction of Aromatic Aldehydes

The reduction of TiCl4(THF)2 with Al in CH2Cl2 gave a green solution of [Ti2(μ-Cl)2Cl4· (THF)4] (1) which was found to promote the reductive homocoupling of aromatic aldehydes to yield symmetrical 1, 2-diols with high diasterepselectivities.

Electrochemical-Voltammetry Behavior of Several Aromatic Aldehydes in Acid Solution

The electrochemical-voltammetry behavior of vanillin, heliotropin, anisaldehyde on the surface of Pt, Au electrodes in acid solution has been studied by means of the electrochemical cyclic voltammetry method. It was found that the electrochemical processes of them are irreversible on both Pt and Au electrodes. The electrochemical activity of vanillin is stronger than heliotropin's and heliotropin's is stronger than anisaldehyde's on Pt electrode. While the electrochemical activity of anisaldehyde is stronger than heliotropin's and vanillin's is the weakest on Au. The results indicate that when they are used as additives for electroplating, they must be consumptive, and it will improve the leveling ability of plating solution and brightness of the deposition layer.

Enantioselective Pinacol Coupling of Aromatic Aldehydes Induced by Chiral Titanium Complexes

Asymmetric pinacol coupling of aromatic aldehydes with TiCl4-Zn in the presence of enantiopure squaric acid amidoalcohols afforded 1, 2-diols in excellent yields with high dl- diastereoselectivities and enantioselectivities in the range of 46-89% ee. Some factors influencing dl-diastereoselectivity and enantioselectivity were discussed.

Asymmetric Baylis-Hillman Reaction between Chiral Activated Alkenes and Aromatic Aldehydes in Me_(3)N/H_(2)O/Solvent Medium

Chiral activated alkene, L-menthyl acrylate and （＋）-N-α-phenylethyl acrylamide, induced asymmetric Baylis-HiUman reaction of aromatic aldehydes was realized at 25℃ for 7 days in Me3N/H2O/solvent homogeneous medium. The corresponding Baylis-Hillman adducts were obtained in good chemical yield with moderate to excellent diastereoselectivity （up to 99% de）.

CsF mediated rapid condensation of 1,3-cyclohexadione with aromatic aldehydes:Comparative study of conventional heating vs.ambient temperature

A mild, efficient and high yielding protocol for the synthesis of 2,2＇-arylmethelene dicyclohexane- 1,3-dione derivatives at room temperature and 9-aryl-1,8-dihydrooctahydroxanthene at conventional heating using cesium fluoride as a catalyst is reported. The major advantages of this reaction are excellent yield, very short reaction time and use of inexpensive catalyst.

Facile, one-pot synthesis of new phenanthridine derivatives through 1,4-dipolar cycloaddition of phenantridine, activated acetylenes, and aromatic aldehydes

A facile, one-pot synthesis of new phenanthridine derivatives by a three-component reaction between phenantridine, dialkyl acetylenedicarboxylates（DAADs）, and aromatic aldehydes is described. The reaction is characterized by mild conditions, high selectivity, and tolerance to various functional groups.

Mechanochemical Reaction of Aromatic Ketones and Aldehydes in the Presence of Zn-ZnCl_2

The solvent-free reactions of aromatic ketones and aldehydes in the presence of Zn-ZnCl2 were performed with the aid of high-speed vibration mill, Retsch MM200 mixer mill and Retsch RM100 mortar grinder to give pinacol coupling and reduction products in varying yields.

Design and Synthesis of New Compounds Derived from Phenyl Hydrazine and Different Aldehydes as Anticancer Agents

In this work we synthesized new derivatives from Phenyl Hydrazine and series of different Aldehydes (derivatives of benzylidenes). The synthesized compounds contain different aromatic Aldehydes which attached by Benzene ring via Hydrazine moiety in glacial acetic acid. These derivatives were characterized by TLC, melting points, Infrared Red, Proton Nuclear Magnetic Resonance, Carbon Thirteen Nuclear Magnetic Resonance and Mass Spectroscopy. Finally, these synthesized derivatives were tested for antiproliferative activity against multiple normal and cancerous cell lines, HepG2 (Liver cancer) and MCF-7 (Breast cancer) cell lines were used for cytotoxic assay.

Efficient Synthesis of Dicycloalkenopyridines:One-pot Multicomponent Condensation of Aldehydes with Cyclic Ketones

Under microwave irradiation, the one-pot multicomponent condensation reaction of three moles of aromatic aldehydes with two moles of cyclic ketones having free a,a＇-methylene positions such as cyclopentanone or cyclohexanone in the presence of ammonium acetate and acetic acid afforded dicycloalkenopyridines with two a-arylidene groups in high yields. Under the similar reaction condition, the reaction of aromatic aldehydes with 1-tetralone having only one a-methylene position alternatively resulted in 10-aryl-2,3：5,6-dibenzoacridines.

STUDIES On THE SOLID-STATE PHOTOCHEMICAL RFACTIONS OF ANTIPYRINE WITH AROMATIC ALDEHYDE

Solid state photochemical reactions of antipyrine with 5-formyl-1,3- dimethyluracil,p-nitrobenzaldehyde and p-hydroxybenzaldehyde have been described.The structures of 4 hey compounds obtained were determined by IR,UV,\+1HNHR,ns and elemental analysis.